CVE-2025-48057
📋 TL;DR
A certificate validation vulnerability in Icinga 2 allows attackers to obtain valid certificates by tricking the system into treating malicious certificate requests as renewals. This enables impersonation of trusted nodes in the monitoring infrastructure. Only affects Icinga 2 installations built with OpenSSL versions older than 1.1.0.
💻 Affected Systems
- Icinga 2
📦 What is this software?
Icinga by Icinga
Icinga by Icinga
Icinga by Icinga
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of monitoring infrastructure with attacker obtaining trusted certificates, enabling man-in-the-middle attacks, data interception, and unauthorized access to monitored systems.
Likely Case
Attacker impersonates trusted Icinga nodes to inject false monitoring data, trigger false alerts, or suppress legitimate alerts, disrupting monitoring operations.
If Mitigated
Limited impact if proper network segmentation and certificate pinning are implemented, though certificate trust chain remains compromised.
🎯 Exploit Status
Exploitation requires ability to send certificate requests to Icinga 2 API endpoints. No public exploit code available at time of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.12.12, 2.13.12, or 2.14.6
Vendor Advisory: https://github.com/Icinga/icinga2/security/advisories
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Stop Icinga 2 service. 3. Update to patched version using package manager or source compilation. 4. Verify OpenSSL version is 1.1.0 or newer. 5. Restart Icinga 2 service. 6. Validate certificate functionality.
🔧 Temporary Workarounds
Upgrade OpenSSL Dependency
linuxUpdate system OpenSSL to version 1.1.0 or newer and rebuild Icinga 2 from source
sudo apt-get update && sudo apt-get upgrade openssl
sudo yum update openssl
Recompile Icinga 2: ./configure && make && make install
Restrict Certificate API Access
linuxLimit network access to Icinga 2 certificate signing endpoints
iptables -A INPUT -p tcp --dport 5665 -s trusted_networks -j ACCEPT
iptables -A INPUT -p tcp --dport 5665 -j DROP
🧯 If You Can't Patch
- Isolate Icinga 2 instances in separate network segments with strict firewall rules
- Implement certificate pinning and monitor for unexpected certificate changes
🔍 How to Verify
Check if Vulnerable:
Check Icinga 2 version: icinga2 --version. If version is below 2.12.12, 2.13.12, or 2.14.6 AND OpenSSL version is below 1.1.0, system is vulnerable.Check Version:
icinga2 --version | grep 'version' && openssl versionVerify Fix Applied:
Verify Icinga 2 version is 2.12.12, 2.13.12, or 2.14.6 or higher: icinga2 --version. Confirm OpenSSL version: openssl version.📡 Detection & Monitoring
Log Indicators:
- Unexpected certificate signing requests
- Certificate renewals from unfamiliar IP addresses
- API authentication failures on certificate endpoints
Network Indicators:
- Unusual traffic to Icinga 2 API port 5665 from untrusted sources
- Certificate requests containing malformed or suspicious data
SIEM Query:
source="icinga2.log" AND ("certificate" AND ("request" OR "renewal")) AND src_ip NOT IN [trusted_ips]🔗 References
- https://github.com/Icinga/icinga2/commit/34c93a2542bbe4e9886d15bc17ec929ead1aa152
- https://github.com/Icinga/icinga2/commit/4023128be42b18a011dda71ddee9ca79955b89cb
- https://github.com/Icinga/icinga2/commit/60f75f4a3d5cbb234eb3694ba7e9076a1a5b8776
- https://github.com/Icinga/icinga2/commit/9ad5683aab9eb392c6737ff46c830a945c9e240f
- https://github.com/Icinga/icinga2/commit/9b2c05d0cc09210bdeade77cf9a73859250fc48d
- https://github.com/Icinga/icinga2/security/advisories/GHSA-7vcf-f5v9-3wr6
